Now the Obama administration is under pressure to prevent security breaches -- like a gate crashing -- from spoiling its 17 holiday parties and 11 open houses in which 50,000 people are expected to shuffle through the "people's house" to toast the holidays.

As the government probes how two wannabe reality TV stars managed to slip into last week's state dinner honoring the Indian prime minister, the White House must reevaluate how it will manage the masses.

White House Press Secretary Robert Gibbs announced Wednesday that the administration will adopt new guidelines to increase vigilance and ensure that only invited guests enter the complex.

The Secret Service, whose chief testified Thursday that the agency had failed to follow established procedures during the state dinner, also pledged to adhere to longstanding security protocol.

"We will ensure that our procedures in place are strictly followed," Darrin Blackford, a Secret Service public affairs officer, told FoxNews.com on Thursday. "There is a system in place where all visitors to the White House are vetted."

William H. Pickle Jr., a former Secret Service agent who headed Vice President Al Gore's detail, said he believes White House security will be at its tightest this holiday season.

"Once you screw up, everyone starts looking and you redouble your efforts," Pickle said in an interview with FoxNews.com.

"If anything, this was a good training exercise," he said, noting that the security breach that allowed Tareq and Michaele Salahi to pass through uninvited last week was caused by human error -- not a systematic failure. "There's a good system in place."

Gibbs said White House staff will now be physically stationed at various checkpoints in collaboration with the Secret Service -- a practice that had long been in place but failed to occur at the Nov. 24 state dinner.

Guests will be "checked off of the list by White House staff," according to White House deputy chief of staff Jim Messina, and "guests whose names are not on the guest list will be assisted by White House staff present at the check point for appropriate resolution."

But Mark Sullivan, director of the Secret Service, acknowledged in testimony before a House panel on Thursday that the agency does not vet all guests entering the complex if a White House aide has vouched for a guest -- which he said happens on rare occasions.

Pickle said all holiday invitees are thoroughly vetted each year by running criminal record checks and by requiring guests to pass through a magnetometer. He said party-goers are screened for chemical and biological weapons -- though he declined to comment on specific technology used to detect such agents.

"You can argue that it can happen again but after what's going on today, I don't see that," he said. "In the long run, this will be good for the service."